The effect of non-covalent functionalization on the thermal conductance of graphene/organic interfaces

The intrinsic interfacial thermal resistance at graphene/organic interfaces, as a result of mismatches in the phonon vibrational spectra of the two materials, diminishes the overall heat transfer performance of graphene/organic nanocomposites. In this paper, we use molecular dynamics (MD) simulation...

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Bibliographic Details
Published in:Nanotechnology 2013-04, Vol.24 (16), p.165702-165702
Main Authors: Lin, Shangchao, Buehler, Markus J
Format: Article
Language:English
Subjects:
Chains
Condensed matter: structure, mechanical and thermal properties
Cross-disciplinary physics: materials science
rheology
Exact sciences and technology
Fullerenes and related materials
diamonds, graphite
Graphene
Graphical user interface
Heat transfer
Lattice dynamics
Materials science
Mechanical and acoustical properties of condensed matter
Mechanical properties of nanoscale materials
Nanocomposites
Octane
Phonons
Phonons in low-dimensional structures and small particles
Physics
Specific materials
Thermal conductivity
Thermal properties of condensed matter
Thermal properties of small particles, nanocrystals, nanotubes
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Summary:The intrinsic interfacial thermal resistance at graphene/organic interfaces, as a result of mismatches in the phonon vibrational spectra of the two materials, diminishes the overall heat transfer performance of graphene/organic nanocomposites. In this paper, we use molecular dynamics (MD) simulations to design alkyl-pyrene molecules that can non-covalently functionalize graphene surfaces in contact with a model organic phase composed of octane. The alkyl-pyrene molecules possess phonon-spectra features of both graphene and octane and, therefore, can serve as phonon-spectra linkers to bridge the vibrational mismatch at the graphene/octane interface. In support of this hypothesis, we find that the best linker candidate can enhance the out-of-plane graphene/organic interfacial thermal conductance by ∼22%, attributed to its capability to compensate the low-frequency phonon mode of graphene. We also find that the length of the alkyl chain indirectly affects the interfacial thermal conductance through different orientations of these chains because they dictate the contribution of the out-of-plane high-frequency carbon-hydrogen bond vibrations to the overall phonon transport. This study advances our understanding of the less destructive non-covalent functionalization method and design principles of suitable linker molecules to enhance the thermal performance of graphene/organic nanocomposites while retaining the intrinsic chemical, thermal, and mechanical properties of pristine graphene.
ISSN:0957-4484
1361-6528
DOI:10.1088/0957-4484/24/16/165702